Over the last thirty years, many new features have been added to the rich set of features already available to communications services subscribers. Such new features include call waiting, call forwarding, three-way calling, speed dialing, voice messaging, and automatic callback, to name a few. The call-waiting feature is perhaps the most widely used communications services feature for many reasons, not the least of which are its relatively low cost (no additional end-user device required) and its simple user interface (user-friendly hook flash). In essence, the call-waiting feature allows a subscriber who is already busy on a first call to be alerted to the presence of a second call in waiting. Such alert typically takes the form of a signal that is transmitted in-band to the call-waiting subscriber, in complete disregard of the conversation that is taking place between the subscriber and the other party of the first call (hereinafter “the first party”). Call-waiting subscribers have always resented the ill-mannered interruption of the call-waiting alert signal. Nevertheless, their apprehension of losing important calls has impelled call-waiting subscribers to tolerate, albeit grudgingly, the brusqueness of the call-waiting alert signal.
The threshold of tolerance of a call-waiting subscriber is quite often ruggedly tested when the subscriber interrupts a first important call to answer a second call presumed to be important, only to find out that the second call is unimportant or, worse yet, a nuisance call. To make matters worse, when the call waiting subscriber has to interrupt an important conversation with the first party to take the call-in-waiting, the unsuspecting second caller more often than not, incurs the wrath of the call-waiting subscriber, even though the second caller could not have prevented the interruption.
Equally bothersome is the impression of benign neglect that may be felt by the first party after being placed on hold for the benefit of the second caller. The feeling of benign neglect is especially intense when the first party knows that the subscriber could have simply ignored the second call in waiting, if the subscriber so desired. However, if the call-waiting subscriber ignores the call in waiting, in an attempt to vitiate any potential feeling of neglect from the first party, the subscriber runs the risk of losing the call in waiting without the benefit of even a message from the caller-in-waiting. This is because the operations of an answering machine (e.g., delivery of a greeting announcement and recording of a message) are triggered when the answering machine receives at least one ringing tone signal from a network office switch. Unfortunately, when a call waiting subscriber is already engaged in a first call, the subscriber's answering machine does not receive the appropriate ringing tone signal to trigger the operations of the subscriber's answering machine.
In response to this problem, some switch manufacturers have introduced the so-called “call waiting id” feature. Basically, the feature provides on a screen of a caller-id box, a display of the name and/or number of a caller in-waiting who is attempting to reach a call-waiting subscriber already engaged in a first call. The call-waiting id feature has certain economic disadvantages and other limitations that make such features unattractive to certain subscribers. For example, the name and/or number information delivered to the call waiting subscriber may be worthless or misleading if the call-in-waiting is originated from a public telephone booth or a telephone set that is not associated with the caller's mobile number, residential number or work number. In addition, the call waiting id feature requires a communications services user to subscribe to two separate communications services features, namely, caller-id and call waiting. Furthermore, some communications carriers charge an additional monthly fee for call-waiting id above and beyond the monthly charges for caller-id and call waiting. Worse yet, a caller-id and call-waiting subscriber who wishes to subscribe to the call-waiting id feature may need to replace his or her caller-id box with a special “call-waiting-id-capable” caller-id hardware to benefit from the call-waiting-id feature. Finally, the call-waiting id feature does not spare the subscriber of the brusqueness of the call-waiting alert signal.
It is thus desirable to provide to a caller-in-waiting cost-effective methods of alerting a call waiting subscriber of his or her incoming call.